From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7642EC28CC2 for ; Wed, 29 May 2019 15:49:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4ED3323BCD for ; Wed, 29 May 2019 15:49:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4ED3323BCD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:56882 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hW0pU-0005or-Gx for qemu-devel@archiver.kernel.org; Wed, 29 May 2019 11:49:28 -0400 Received: from eggs.gnu.org ([209.51.188.92]:54875) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hW0n8-0004V3-Sb for qemu-devel@nongnu.org; Wed, 29 May 2019 11:47:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hW0n7-00053Q-RW for qemu-devel@nongnu.org; Wed, 29 May 2019 11:47:02 -0400 Received: from relay.sw.ru ([185.231.240.75]:43132) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hW0n7-00051r-JQ; Wed, 29 May 2019 11:47:01 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1hW0n2-0004iP-KH; Wed, 29 May 2019 18:46:56 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Wed, 29 May 2019 18:46:52 +0300 Message-Id: <20190529154654.95870-6-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20190529154654.95870-1-vsementsov@virtuozzo.com> References: <20190529154654.95870-1-vsementsov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 Subject: [Qemu-devel] [PATCH v8 5/7] block/io: refactor wait_serialising_requests X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: fam@euphon.net, kwolf@redhat.com, vsementsov@virtuozzo.com, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org, jsnow@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Split out do_wait_serialising_requests with additional possibility to not actually wait but just check, that there is something to wait for. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Max Reitz --- block/io.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/block/io.c b/block/io.c index 3134a60a48..c347f90722 100644 --- a/block/io.c +++ b/block/io.c @@ -720,12 +720,13 @@ void bdrv_dec_in_flight(BlockDriverState *bs) bdrv_wakeup(bs); } -static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) +static bool coroutine_fn do_wait_serialising_requests(BdrvTrackedRequest *self, + bool wait) { BlockDriverState *bs = self->bs; BdrvTrackedRequest *req; bool retry; - bool waited = false; + bool found = false; if (!atomic_read(&bs->serialising_in_flight)) { return false; @@ -751,11 +752,13 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) * will wait for us as soon as it wakes up, then just go on * (instead of producing a deadlock in the former case). */ if (!req->waiting_for) { - self->waiting_for = req; - qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); - self->waiting_for = NULL; - retry = true; - waited = true; + found = true; + if (wait) { + self->waiting_for = req; + qemu_co_queue_wait(&req->wait_queue, &bs->reqs_lock); + self->waiting_for = NULL; + retry = true; + } break; } } @@ -763,7 +766,12 @@ static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) qemu_co_mutex_unlock(&bs->reqs_lock); } while (retry); - return waited; + return found; +} + +static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) +{ + return do_wait_serialising_requests(self, true); } static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, -- 2.18.0